Taiwan heads to the polls on Saturday in a closely-watched general election looks set to strain its already fraught relationship with Asian giant China.

With the pro-democracy Democratic Progressive Party (DPP) set to win the presidential post, ties between the two territories - which have improved since Taiwan's current, pro-China president Ma Ying-jeou of the Nationalist Party (KMT), became the leader in 2008 - will be in focus.

Cross-straits relations have been testy since the end of the Chinese civil war in 1949, when the Nationalist Party (KMT) was forced by Communist Party of China to retreat to Taiwan. No armistice or peace treaty has ever been signed to mark the end of the conflict and China views Taiwan as a renegade province that may be reclaimed by force if necessary.

And they could be set to get testier. The most recent opinion polls showed a double-digit lead for the pro-independence DPP's Tsai Ing-wen over the KMT's Eric Chu and the People First Party's James Soong.

Here's how the candidates compare:

Tsai Ing-wen

Sam Yeh | AFP | Getty Images

Tsai Ing-wen, presidential candidate for Taiwan's main opposition Democratic Progressive Party (DPP), joins hands with supporters during a rally in southern Kaohsiung on January 9, 2016.

A lawyer by training, DPP's Tsai is contesting for the post for the second time and tipped by opinion polls to become the first female president of Taiwan.

According to reports, she was fast-tracked to senior posts within the Taiwanese government from the start of her career, becoming the territory's chief trade negotiator in her 30s and the top China affairs minister in her 40s.

In line with DPP's pro-democracy position, she is seen to be a proponent of an independent Taiwan, although her stance has softened as the polls near in order to win over voters concerned about strained cross straits ties.

Tsai is also known for her support for LGBT rights and same-sex marriage.

Eric Chu

Billy H.C. Kwok | Bloomberg | Getty Images

Eric Chu, presidential candidate and chairman of Taiwan's ruling party Kuomintang, listens during an interview at the party's headquarters in Taipei, Taiwan, on Friday, Dec. 11, 2015.

The mayor of New Taipei City, the most populous city in Taiwan, Chu is running on the KMT ticket.

From a political family, Chu was parachuted into the race in October when former candidate Hung Hsiu-chu was unceremoniously dropped by the party due to her poor performance in opinion polls.

A party with roots tracing back to the fall of the last imperial dynasty in China, the KMT envisions eventual reunification with the mainland — although China's communist rule of the last 66 years has stalled any such development and spurred the rise of intra-party factions.

In line with Ma's policies toward China, Chu is championing closer ties with China in the hope of lifting Taiwan out of its economic doldrums.

James Soong

Sam Yeh | AFP | Getty Images

James Soong, presidential candidate from the People First Party (PFP), gestures during a press conference in Taipei on January 12, 2016.

No stranger to the presidential race, Soong is a veteran KMT member who is joining the leadership fray for the third time this year — this time for the People's First Party, a party that he set up after he lost the 2000 presidential election.

In 2000, Soong ran as an independent candidate, splitting votes between himself and KMT's Lien Chan, thus paving the way for Taiwan's first non-KMT president, Chen Shui-bian from DPP.

Soong is known for his pro-Beijing stance, as was cemented by a visit to mainland China in 2005, where he met with then-president Hu Jintao.